David e



(No Model.)

D. R. DOWNER.

Duplex Telegraph Repeater;

-No. 243,530. Patented June 28,1881.

.Davo'ol Downer,

N. PETERS. Pholo-Lhhcgnphnr. Washington. D- (l UNITED STATES PATENTOFFICE.

DAVID R. DOWNER, OF ELIZABETH, NEW JERSEY.

DU PLEX-TELEG RAPH REPEATER.

SPECIFICATION formingpart of Letters Patent No. 243,530, dated June 28,1881.

Application filed April 30, 1881.

To all whom it may concern:

Be it known that I, DAVID R. DOWNER, a citizen of the United States,residing at Elizabeth, in the county of Union and State of New Jersey,have invented certain new and useful Improvements in Duplex andQuadruplex Telegraphs, of which the following is a specification.

My invention consists in a method of and apparatus for combining abranch or auxiliary line with the transmitting and receiving apparatusat the terminal station of a duplex or quadruplex telegraph, whereby theoperator at an auxiliary station may transmit or receive communicationsover a single branch wire, and directly through the duplex or quadruplexcircuit, without the necessity of retransmission at the terminalstation, and in providing means whereby the branch line may bedisconnected from the apparatus at the terminal station of the duplex orquadruplex line when required.

The accompanying drawing is a diagram representing the apparatus at oneterminal station of a quadruplex line and the combination of a branchline and of the apparatus at a branch station therewith in accordancewith the principles of my invention. v

In the drawing I have shown the ordinary arrangement of apparatus forworking quadruplex at one terminal station of a main line, thecircuit-connections being shown in dotted lines.

L represents the main line; M, the non-polarized differential receivinginstrument P, the polarized difierential receivin g-instrument; T, thepole-changing transmitter; T the single-current transmitter; E and e,the greater and the lesser sections, respectively, of the main battery;R, the rheostat in the artificial line; 0, the condenser connected withthe same, and G the ground-connection. K and K are thetransmitting-keys, which respectively operate the transmitters T and TAll the parts thus far referred to are'well known and in common use, andby themselves constitute no part of my invent-ion, which .relates solelyto the combination therewith of apparatus and .circuits by means ofwhich an operator at an auxiliary station upon abranch line is enabledto work directly without man- (No model.)

ual retransmission over the duplex or quadruplex circuit. Ihaverepresented such a branch line as connected with onetransmitting-instrument, T, and one receivinginstrument, P, of aquadruplex apparatus, which of themselves constitute a duplex apparatusonly; but it is to be understood that another branch line might beattached in the same manner to the second transmitter, T and a secondreceiver, M, of the quadruplex without any modification other than amere duplication of the apparatus.

In the drawing the polarized receiving-instrument P is represented asopening and closing the circuit of a local battcry, f, through anelectro-magnet, s. In the ordinary arrangement the armature-lever S ofthe electro-magnet s is employed simply to produce sounds, the apparatusconstituting, in fact,an ordinary Morse sounder. Without in the leastinterfering with its usefulness for this purpose, I have placed upon thesaid lever an insulated spring, g, which normally rests against a stop,0*, formed upon the end of the lever. When the electro-magnet s attractsits armature the spring q is brought against the fixed stop 12, makingelectrical contact therewith and at the same time breaking the normallyexisting contact with the stopjr. This portion of the apparatus as thusarranged performs the double ot'fice of a receiving-sounder for theterminal station and a transmitter, whereby the signals areautomatically repeated into the branch line, as will be hereinaftershown. The battery of the branch line is divided into two sections, Band I), the latter, which is the smaller section, may be composed of twoor three cells, the number required being no greater than thatordinarily used for the local battery for operating the transmitter. Thenumber of cells required for the larger section, B, will depend upon thelength or resistance of the branch line of which it constitutes the mainbattery. I

W is a switch, by means of which the branch line may conveniently beplaced in connection with the apparatus or disconnected therefrom at thewill of the operator at the terminal duplex station, as hereinafterexplained.

The apparatus at the auxiliary or branch station consists of an electromagnet, m, which may constitute a portion of a receiving-instrument ofany suitable character. '10 is the transmitting-key, and g is theground-connection. l is the branch line extending from the terminalstation of the duplex or quadruple-x line to the branch or auxiliarystation. This may be of any required length. When the hand-s witch .W isplaced upon the contact-point x, as shown in the figure, the apparatusis in readiness for use. In this case the circuit of the branch line maybe traced as follows: From the ground at G by the wire 1,battery-section Z), and wire 2 to electro-m agnet t of transmitter T,thence by wire 3, through key K, and by wire 4 to switch W, thence bycontact-point m and wire 5 to contact-sprin g g. The spring q will,therefore, be in permanent connection with the battery B b.

It will be understood from the foregoing description that when acommunication is to be sent directly to the branch station from thestation at the distant end of the main line L the operator at the latterpoint has only to transmit the same by means of his double-currenttransmitter. The signals so sent will be received upon the polarizedrelay 1? and repeated through the local circuit upon the electro-magnets. The armature-lever S of this electro-magnetacts, in turn, as a key,and retransmits the signals into the branch line L by bringing thespring q into contact with the stop a each time that a signal is sent.The signals are received by the operator at the branch station and readfrom his instrument in the usual manner. y

In order to prevent the breaking and closing otflthe circuit of thebranch line from actuating the transmitter T, which would have theeffect of retransmitting the received signals to the distant station, aconductor consisting of a wire, 6, is connected with the restingcontactstop 1" upon the lever S of the branch-line transmitter, whichconductor extends to a point within the branch-line battery, or intermediate between its poles, it being preferably attached at the same pointas the wireleading from the contact-point 1 ofthe switch XV. Thus, whenever the electro-magnet 8 ot' the branch-line transmitter releases itsarmature, and thus breaks the circuit of the branch line Z, the contactspring q at the same instant touches its resting contact 1' and closesthe circuit of the battery-section I) through the wires 2, 3, 4, 5, and6, including the actuating electro-magnet of the transmitter T, and thuskeeps the mainline transmitter closed whenever the branchlinetransmitter is open, by which means the unnecessary repetition of thesignals over the main line in the opposite direction is prevented.

When a communication is to be sent directly from the branch station tothe distant station upon the line L, the operator at the distant station first closes the key of the pole-chan gin g transmitter to his owninstrument, which, in turn, closes the local circuit of the local batteryf by means of the polarized relay P, and

- the stop 1".

thus causes the electromagnet s to attract its armature'S. This bringsthe contact-spring (1 into contact with the stop a, at the same timebreaking its previously-existing contact with This will cause acontinuous current from the batteryB b to traverse the branch line andinstrument. It, now, the operator at the branch station transmits acommunication by manipulating his key is, his signals will pass over theline 1, wire 5, switch W, wires 4 and 3, and through the electro-magnett. The latter electro-magnet operates the transmitter T as usual, andthus repeats the signals from the key over the line L to the distantstation.

Nhenever it is desired to disconnect the branch line from the apparatusit is only necessary For the operator at the terminal main station toturn the hand-switch W from the contact a' to the contact y. This placesthe key K and the electro-magnet j. of the double current transmitter Tin a local circuit consisting of wires 2, 3, and 4, and including onlythe smaller section, b, of the battery, the larger section, B, beingthrown out of circuit. v

When the operator at the branch station is transmitting to the distantstation over the line L the latter may interrupt him at any time. byusing his pole-changing key, which will instantly break the circuit ofthe branch line by means of the armature-lever S.

It is obvious that any required number of stations may be placed uponthe branch line l, each being provided with a key, 7.", and areceiving-instrument, m; and if the line is of sufficient length torender it necessary or desirable, a main battery may be placed atitsremote terminal, g.

I claim as my invention 1. In a duplex or quadruplex telegraph, thecombination, substantially as hereinbefore set forth, of a main-linetransmitter, an electromagnet for actuating said transmitter, a mainlinereceiving-instrument, a branch-line transmitter actuated by saidreceiving-instrument, and a branch line which includes within itscircuit the electro-magnet that actuates the main-line transmitter andalso the circuit controlling attachments of the branch-line transmitter.

2. In a duplex or quadruplex telegraph, the combination, substantiallyas he'reinbefore set forth, of a main-line transmitter, an electromagnetfor actuating said transmitter, a branch line, including saidelectro-magnet in its circuit, a battery connected with said branchline, having one of its poles to earth, a key, and a hand-switchconnected with said key for disconnecting the latter l'rom the branchline and connecting it with a local branch, including a section of thebattery.

3. In a duplex or quadruplex telegraph, the combination, substantiallyas hereinbefore set forth, of a branchline transmitter provided with acontact sprin g playing between a restin g and a working contact, abranch line connected with said working contact, a conductor extendingfrom said eontact-springto abranch- I In testimony whereof I havehereunto subline battery, a main-line transmitter actuated scribed myname this 29th day of-April, A. D. by an eiectro-magnet included in thecircuit of 1881.

said conductor, and a conductor extending DAVID R. DOWNER. 5 from theresting contact on the branch-line I Witnesses:

transmitter to an intermediate point between JOHN J. TRAOY,

the terminals of said battery. MILLER O. EARL.

